Help please I don’t understand this. The last columm

You can calculate the total number of atoms by multiplying the subscripts by the element. I will use the first example to explain this.

Fe2(SO3)3

- Fe has the subscript 2, so there are 2 Fe atoms

- The subscript 3 (after the SO3 bracket) will be multipled in, so multiple everything in the bracket by 3

- S has no subscript after it, so it contains one atom. However, due to the subscript 3 after the bracket, we multiple this by 3. So S has 3 atoms.

- O has a 3 subscript after it, so it contains 3 atoms. However, we have to make sure to multiple it by 3. Therefore, O will have 9 atoms.

If we add all these values we will get the total number of atoms. 2 + 3 + 9 = 14. Therefore, the total number of atoms is 14.

pure substance: iron,copper

impure substance: water,charcoal

because u need two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei to form isotopes.

so since they all have the same shape? i mean maybe because m& m and reeses are both chocolates